RV News RVBusiness 2021 Top 10 RVs of the Year, plus 56 additional debuts and must-see units → ×
 

Go Back   Thor Forums > Thor Tech Forums > Motorhome Tech Topics
Click Here to Login
Reply
 
Thread Tools Display Modes
 
Old 11-07-2019, 03:44 PM   #1
Senior Member
 
WearyTraveler's Avatar
 
Brand: Thor Motor Coach
Model: Thor Outlaw 38RE
State: West Virginia
Posts: 256
THOR #17154
Alternator and house batteries

While we’re sitting here watching the world go by...

Yesterday, I posed (and you folks answered perfectly) the question about the inverter. So - we drove for about 8 hours with the inverter on and the fridge powered. We were smiling as we cruised down the highway...

When we stopped last night and I checked the batteries before firing up the gen, the gauge (lights, actually) showed that the batteries were only half charged.

I was assuming that the V’s alternator would charge the house batteries on the fly.

Did we screw up by doing this? Or doesn’t the alternator keep up with battery power depletion?
__________________

__________________
WearyTraveler is offline   Reply With Quote
Old 11-07-2019, 04:00 PM   #2
I Think We're Lost!
 
Bob Denman's Avatar
 
Brand: Still Looking
Model: Tiffin Wayfarer 24 BW
State: New York
Posts: 17,873
THOR #8860
Question: What were those indicator lights showing for a state of charge: when you first started?
The V-10's alternator has a primary job: to keep the chassis battery up to snuff.
I don't know what it's excess capacity is; but (depending upon power usage): you could have been throwing more at it, than it could handle.
__________________

__________________
Good Sam Member 843599689
Current coach: Tiffin Wayfarer 24 BW
Bob Denman is offline   Reply With Quote
Old 11-07-2019, 05:21 PM   #3
Senior Member
 
Brand: Thor Motor Coach
Model: Gemini 24TX (Formerly)
State: California
Posts: 1,433
THOR #5821
If its setup correctly, when running your engine, you should be charging all batteries on-board. I know mine does, as I can see the voltage increase in the inverter display when the engine is running. If you have an inverter, just check the voltage display with the engine off and again when its running.
__________________
Laco is offline   Reply With Quote
Old 11-07-2019, 07:19 PM   #4
Site Team
 
16ACE27's Avatar
 
Brand: Thor Motor Coach
Model: ACE 27.1
State: Florida
Posts: 5,400
THOR #7035
The engine will charge the house batteries if:
The USE/STORE switch is in USE (batteries not disconnected from the DC buss) and;
The Battery Isolation Manager (BIM) or other method of cross-connecting the house and chassis batteries for charging and isolating them when discharging, is working correctly.
__________________
Ted & Melinda
2016 ACE 27.1
2016 Chevy Sonic Toad
2020 Chevy Colorado Z71 Trail Runner Alternate Toad
16ACE27 is online now   Reply With Quote
Old 11-07-2019, 07:46 PM   #5
I Think We're Lost!
 
Bob Denman's Avatar
 
Brand: Still Looking
Model: Tiffin Wayfarer 24 BW
State: New York
Posts: 17,873
THOR #8860
Quote:
Originally Posted by 16ACE27 View Post
The engine will charge the house batteries if:
The USE/STORE switch is in USE (batteries not disconnected from the DC buss) and;
The Battery Isolation Manager (BIM) or other method of cross-connecting the house and chassis batteries for charging and isolating them when discharging, is working correctly.
...Provided that the chassis engine is running long enough to do so...
__________________
Good Sam Member 843599689
Current coach: Tiffin Wayfarer 24 BW
Bob Denman is offline   Reply With Quote
Old 11-07-2019, 08:20 PM   #6
Member
 
Brand: Thor Motor Coach
Model: Mandalay
State: Florida
Posts: 41
THOR #11268
Not everything is at it seems..

We purchased our used MH a couple of years ago. I asked about the house batteries and were told they only charge when the genset is running or plugged into shore power. What a pita always on trips and worrying about my house batteries going dead and having to hurry to shore power.

A few months ago I began doing some research and found out most MH have the engine alternator charge the house batteries...

I was in CW out west and saw a tech so I asked him his thoughts.. He went to my coach and started checking it then came to me stating mine did not have a fuse spot. He said mine was not equipped for alternator charging.. Hmmm... I later looked at the fuse holder and the tech was holding the cover up side down.. duhhh.. I did have a fuse in the slot.

A couple of days later I was looking under my dash for a loose camera connection. I saw another fuse panel with a fuse that had a red led light next to it illuminated. I knew that was an indicator the fuse is bad. I replaced the fifty-cent fuse not knowing what it went to. Viola other things started working and my alternator began charging my batteries. Now when I travel my house batteries stay charged.

The moral is just because others tell you it will not work find out on your own through investigating the problem.

3 CW, and independent dealer and Thor steered me wrong. I small fuse and had I not had the ignition key on trying to find the loose camera connection I would never have seen the red light on.

Keep plugging until you find the problem and good luck
__________________
tanman32225 is offline   Reply With Quote
Old 11-07-2019, 08:42 PM   #7
Senior Member
 
Brand: Thor Motor Coach
Model: Hurricane 31S
State: Texas
Posts: 2,342
THOR #6411
Quote:
Originally Posted by WearyTraveler View Post
While we’re sitting here watching the world go by...

Yesterday, I posed (and you folks answered perfectly) the question about the inverter. So - we drove for about 8 hours with the inverter on and the fridge powered. We were smiling as we cruised down the highway...

When we stopped last night and I checked the batteries before firing up the gen, the gauge (lights, actually) showed that the batteries were only half charged.

I was assuming that the V’s alternator would charge the house batteries on the fly.

Did we screw up by doing this? Or doesn’t the alternator keep up with battery power depletion?
Your 175 amp alternator has about 1,700 watts @ 2,400 engine RPM (500 watts @ idle rpm) usable output, so all is fine to run the fridge IF you are not using other things in the coach. The problem is dash A/C draws about 500 watts, headlights 120 watts, TV 65 watts, fridge 350 watts unless your door heaters are on then 660 watts. If the fridge in defrost mode then 1400 watts. Your MSW inverter is about 60% efficient when powering electric motors, so 635 watts of alternator power to power the fridge through the alternator.


You are going to have to learn about battery management if you are going to dry camp. Flooded batteries start to loose some of their ability to accept a full charge the day they are filled with acid. The deeper you discharge them the more life you take out of them. The typical life of a flooded battery discharged to 50% 60 days a year is usually 2 years. They don't fail; they just don't recharge to anything like full capacity. Any flooded battery will age rapidity if left 24 hours or longer in a partially discharged state. A new battery discharged to near zero a couple times will likely never recover.
The best check of the house batteries is when there is no power charging the batteries (engine off, generator off and not on shore power). Turning the inverter on will show actual battery voltage - 12.8 volts fully charged; 12.2 volts 50% charged; 12.1 volts 25% charge and 11.9 volts 0% charged. More info @ <https://www.batterystuff.com/kb/articles/battery-articles/battery-basics.html>
__________________

__________________
Jim & Roy Davis
2016 Hurricane 31S
1961 Rampside in tow
Beau388 is online now   Reply With Quote
Reply

Tags
newbie, power

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


» Featured Campgrounds

Reviews provided by

Disclaimer:

This website is not affiliated with or endorsed by Thor Industries or any of its affiliates. This is an independent, unofficial site.




All times are GMT. The time now is 04:10 PM.


Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2021, vBulletin Solutions, Inc.
Content Relevant URLs by vBSEO 3.6.0 PL2
×